The first weekend of summer will be a busy one, with outdoor activities and road and transit work potentially slowing down your appointments with fun.

A cooling front arriving Friday afternoon could bring thunderstorms, followed by more typical summer weather through the weekend, the Capital Weather Gang predicts.

If you’re heading to Camden Yards for the weekend series between the Nationals and the Orioles, hanging around the District for Saturday afternoon’s Mississippi on the Mall party, or going to Centennial Park in Howard County for the Sunday morning triathlon, watch for lane closings and paving projects.

If you crave air-conditioned entertainment, the week-long Silverdocs documentary festival at the American Film Institute in Silver Spring ends Sunday. There's plenty of parking nearby, and the Silver Theatre is just a few blocks from the Red Line station, but note the Metro weekend delays listed below.

If you don’t have plans yet, check our Going Out Guide, the Beach Guide, the best summer concerts calendar and the guide to Washington’s best rooftop bars.

The highlight of our traffic and transit issues for the weekend and beyond is the paving project on the Capital Beltway in Virginia.

Virginia Beltway closings

The Wilson Bridge project is planning to shift the THRU/LOCAL split on the Beltway’s outer loop to just west of the Eisenhower Connector, after the Van Dorn Street exit. This move will clear room for the final paving of the outer loop lanes. But it’s very likely to cause big traffic backups as it is set up over the weekend.

On Thursday night, the outer loop THRU lanes will be closed to prepare for the weekend work.

From 9 p.m. Friday until 5 a.m. Monday morning, those lanes will close again, and the LOCAL lanes between Van Dorn Street and just after Telegraph Road will be reduced to one lane.

All outer loop traffic will be routed onto this single lane for the entire weekend.

To ease congestion, the ramp from I-95 North to the outer loop at the Springfield interchange will be closed between 7 a.m. and 10 p.m. Saturday and Sunday. All northbound I-95 traffic will be routed onto the inner loop, toward Tysons Corner and the American Legion Bridge.

Drivers also could continue onto I-395 North, which leads to the 14th Street Bridge and the Southeast-Southwest Freeway in the District.

But the weekend work just sets up the paving project..

From Monday until July 30, the two outer loop THRU lanes will be open in their final configuration, but only one LOCAL lane will be open from the split to just past Telegraph Road.

Only those who need to access Telegraph Road, Route 1 or I-295/National Harbor should use the single LOCAL lane.

The ramp from the Eisenhower Connector to the outer loop will be closed until July 30. If the schedule holds, then on July 30, all lanes will be open in their final configuration.

Metro weekend delays

For the third time this month, free shuttle buses will replace trains between East Falls Church and West Falls Church, while crews work on the connection to the new Silver Line. Meanwhile, trains will share tracks around work zones on parts of the Blue and Red lines.

This will create travel delays from 10 p.m. Friday through the rail system’s midnight closing Sunday.

Orange Line: Trains will operate between Vienna and West Falls Church and between East Falls Church and New Carrollton at the regular weekend times, Metro says. If you use the shuttle buses as a connection, add about 20 extra minutes to your normal travel time.

The last eastbound train will leave Vienna 20 minutes earlier than normal, at 2:05 a.m. Saturday and Sunday (that’s the Friday and Saturday night owl service), and at 11:05 p.m. Sunday.

Red Line: Trains will share a track between Judiciary Square and Rhode Island Avenue, and between Medical Center and Grosvenor. They are scheduled to leave the ends of the line about every 20 minutes. Add about 10 minutes of extra travel time because of the work zones, the transit authority says.

From 9:30 6:30 p.m. Saturday and Sunday, more trains will be in service between Medical Center and Judiciary Square. Between those stations, trains should arrive at platforms about every 10 minutes.

Blue Line: Trains will share a track between Stadium-Armory and Addison Road. They are scheduled to leave the ends of the line every 20 minutes. Add about 15 minutes of additional travel time because of the work zone.

Closing at Navy Yard station

The Green Line’s Navy Yard station will close at 10 p.m. Saturday, and the station’s Half Street entrance will be closed at various times throughout the weekend for a security drill, Metro says.

Aside from the station closing, Green Line trains will operate as usual along the rest of the line.

There may be some street closings around Navy Yard station for the drill.

After 10 p.m. Saturday, Metro will operate free shuttle buses between Navy Yard and Waterfront. The station is scheduled to reopen at 7 a.m. Sunday, though the drill in the area will continue till 12:30 p.m. Sunday.

Fort Totten traffic shift

The District Department of Transportation is working on the final paving along South Dakota Avenue NE between Riggs Road and Kennedy Street just east of the Fort Totten Metro station.

This is the last big phase of the reconstruction of the South Dakota Avenue/Riggs Road interchange into an intersection.

Watch for intermittent lane closings and temporary traffic shifts on South Dakota Avenue during the paving. A minimum of one traffic lane will be kept open in each direction at all times. Once the paving is done, traffic will be shifted into the final configuration.

Metro crash victims plaque

Not far away, a ceremony is scheduled for 11 a.m. Friday to unveil a plaque in memory of the victims of the 2009 Red Line crash.

The New Hampshire Avenue/Charles Langley Bridge will be closed to traffic from 10 a.m. to 1 p.m. Friday, but the bridge will remain open to bikes and pedestrians. The motor traffic will be detoured around the bridge.

Curbside parking on the 5700 block of First NE between McDonald and Madison will be restricted between 8 a.m. and 2 p.m.

Dulles Access Highway lane shift

The Dulles Metrorail project (the Silver Line) plans to permanently shift eastbound traffic on the Dulles Access Highway near the Wiehle Avenue station now under construction in the highway median.

The traffic shift is scheduled for 8 p.m. Friday to 5 a.m. Saturday. This will require alternating left and right lane closings during the night.

Police will be there to make sure drivers slow down as they approach the work zone.

17th Street at National Mall

The National Park Service plans to shut 17th Street between Constitution and Independence avenues from 8 a.m. to noon Saturday to install new lane restrictions that are part of the levee construction project.

Then for about two months, both southbound lanes on 17th Street will be closed to all traffic. The northbound lanes will be converted to one lane in each direction.

No work will be done on July 3, 4 and 5, but the lane restrictions still will be in place. The entire project is scheduled to be completed late this year.

Avoid Baltimore Harbor Tunnel

As you drive to or through Baltimore this summer, avoid I-895 and the Baltimore Harbor Tunnel, site of a big construction project. Instead, use I-95 and the Fort McHenry Tunnel.

The lane closings for preservation work on the steel bridge deck south of the Harbor Tunnel could add an hour to trips during peak times. The work began this week and will continue into early fall.

Bay Bridge

A summer travel season reminder: The best times to use the Bay Bridge are Thursdays and Fridays before 10 a.m. and after 10 p.m., Saturdays before 7 a.m. and after 5 p.m., and Sundays before 10 a.m. and after 10 p.m.

Eastern Shore paving

The Maryland State Highway Administration is paving a mile and a half of eastbound Route 50 from Rockawalkin Road to the western end of the Salisbury Bypass in Wicomico County. The work is scheduled to be done by the end of the month.

Crews will close a single lane as needed Mondays through Thursdays from 7 a.m. to 4 p.m., but they won’t work on Fridays because of the heavy summer traffic.